Periprosthetic Joint Infection

Excerpt

Periprosthetic joint infection (PJI) is a unique clinical entity, markedly different from infections involving native bones or joints. PJI is characterized by a complex interplay between microbes, predominantly bacteria but occasionally fungi, and the host immune response. Only a minimal microbial burden is required to initiate a PJI; etiologic organisms can adhere to the surfaces of arthroplasty components and form biofilms. Biofilms notoriously exhibit a marked resistance to a wide array of antimicrobial agents and are adept at avoiding innate immune defenses. The offending microorganisms in PJI typically originate from the skin microbiome and may be introduced during the perioperative phase of the implantation procedure. Alternatively, these pathogens can seed the implant postoperatively via hematogenous dissemination or direct inoculation from adjacent infected tissues.

There is no uniformly accepted definition for PJI. The clinical presentation of PJI varies; the classical features of infection, such as fever, leukocytosis, and signs of sepsis, are often absent. A prosthesis is a foreign body, and its mere presence is a risk factor for infection. The microbial load needed to produce an infection in a prosthetic joint is much less than that for a native joint.

The strongest indicating factor of a PJI is a joint aspirate or surgically obtained periprosthetic material that yields a microorganism when cultured. Other findings indicating a PJI include a sinus tract communicating with the joint space, wound dehiscence, gross purulence, prosthetic loosening, synovial fluid leukocytosis with neutrophilia, and elevated serum inflammatory markers. However, failure to identify an etiologic pathogen does exclude the presence of PJI.

Periprosthetic joint infections are a significant clinical problem. PJIs significantly increase morbidity and mortality and have surpassed polyethylene wear as the primary indication for revision arthroplasty. This activity will review the epidemiology, etiology, pathophysiology, evaluation, and management of PJI and highlight the role of the interprofessional healthcare team in reducing the risk of PJI development and caring for patients who develop this problematic complication of joint replacement.